Methods, systems, and devices for limiting torque in robotic surgical tools

ABSTRACT

Various exemplary methods, systems, and devices for limiting torque in robotic surgical tools are provided. In general, a surgical tool can be configured to releasably and removably couple to a robotic surgical system. The robotic surgical system can include a motor configured to provide torque to the surgical tool to drive two different functions of the surgical tool. The surgical tool can include two torque limiting mechanisms, each associated with the motor, each associated with one of the functions, and each configured to limit an amount of the torque from the motor that drives the function associated therewith.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. patent application Ser.No. 15/237,661 entitled “Methods, Systems, and Devices for LimitingTorque in Robotic Surgical Tools” filed Aug. 16, 2016, which is herebyincorporated by reference in its entirety.

FIELD

Methods and devices are provided for robotic surgery, and in particularfor methods, systems, and devices for limiting torque in roboticsurgical tools.

BACKGROUND

Minimally invasive surgical (MIS) instruments are often preferred overtraditional open surgical devices due to the reduced post-operativerecovery time and minimal scarring. Laparoscopic surgery is one type ofMIS procedure in which one or more small incisions are formed in theabdomen and a trocar is inserted through the incision to form a pathwaythat provides access to the abdominal cavity. The trocar is used tointroduce various instruments and tools into the abdominal cavity, aswell as to provide insufflation to elevate the abdominal wall above theorgans. The instruments and tools can be used to engage and/or treattissue in a number of ways to achieve a diagnostic or therapeuticeffect. Endoscopic surgery is another type of MIS procedure in whichelongate flexible shafts are introduced into the body through a naturalorifice.

Although traditional minimally invasive surgical instruments andtechniques have proven highly effective, newer systems may provide evenfurther advantages. For example, traditional minimally invasive surgicalinstruments often deny the surgeon the flexibility of tool placementfound in open surgery. Difficulty is experienced in approaching thesurgical site with the instruments through the small incisions.Additionally, the added length of typical endoscopic instruments oftenreduces the surgeon's ability to feel forces exerted by tissues andorgans on the end effector. Furthermore, coordination of the movement ofthe end effector of the instrument as viewed in the image on thetelevision monitor with actual end effector movement is particularlydifficult, since the movement as perceived in the image normally doesnot correspond intuitively with the actual end effector movement.Accordingly, lack of intuitive response to surgical instrument movementinput is often experienced. Such a lack of intuitiveness, dexterity, andsensitivity of endoscopic tools has been found to be an impediment inthe increased the use of minimally invasive surgery.

Over the years a variety of minimally invasive robotic systems have beendeveloped to increase surgical dexterity as well as to permit a surgeonto operate on a patient in an intuitive manner. Telesurgery is a generalterm for surgical operations using systems where the surgeon uses someform of remote control, e.g., a servomechanism, or the like, tomanipulate surgical instrument movements, rather than directly holdingand moving the tools by hand. In such a telesurgery system, the surgeonis typically provided with an image of the surgical site on a visualdisplay at a location remote from the patient. The surgeon can typicallyperform the surgical procedure at the location remote from the patientwhilst viewing the end effector movement on the visual display duringthe surgical procedure. While viewing typically a three-dimensionalimage of the surgical site on the visual display, the surgeon performsthe surgical procedures on the patient by manipulating master controldevices at the remote location, which master control devices controlmotion of the remotely controlled instruments.

While significant advances have been made in the field of roboticsurgery, there remains a need for improved methods, systems, and devicesfor use in robotic surgery.

SUMMARY

In general, methods, systems, and devices for limiting torque in roboticsurgical tools are provided.

In one aspect, a surgical system is provided that in one embodiment atool driver of a robotic surgical system. The tool driver is configuredto releasably and replaceably couple to a surgical tool including anelongate shaft with an end effector at a distal end thereof. The tooldriver includes a first motor, a first actuator configured to be drivenby the first motor to actuate a first function of the end effector, afirst torque limiting mechanism that sets a first torque threshold forthe first actuator, a second actuator configured to be driven by thefirst motor to actuate a second function of the end effector, and asecond torque limiting mechanism that sets a second torque threshold forthe first actuator that is different from the first torque threshold.

The surgical system can have any number of variations. For example, thefirst motor can be configured to selectively shift between engagementwith the first actuator to drive the first actuator without driving thesecond actuator and engagement with the second actuator to drive thesecond actuator without driving the first actuator.

For another example, the first function can be closing of the endeffector at a first speed, and the second function can be closing theend effector at a second speed that is greater than the first speed. Inat least some embodiments, the first torque threshold can be greaterthan the second torque threshold.

For yet another example, the tool driver can include a third torquelimiting mechanism that sets a third torque threshold for the firstactuator that is different from the first torque threshold. The firsttorque limiting mechanism but not the third torque limiting mechanismcan be configured to be engaged by the first actuator when the firstactuator is being driven to rotate in a first direction, and the thirdtorque limiting mechanism but not the first torque limiting mechanismcan be configured to be engaged by the first actuator when the firstactuator is being driven in to rotate in a second direction that isopposite to the first direction. In at least some embodiments, the tooldriver can include a fourth torque limiting mechanism that sets a fifthtorque threshold for the second actuator that is different from thesecond torque threshold. The second torque limiting mechanism but notthe fourth torque limiting mechanism can be configured to be engaged bythe second actuator when the second actuator is being driven to rotatein the first direction, and the fourth torque limiting mechanism but notthe second torque limiting mechanism can be configured to be engaged bythe second actuator when the second actuator is being driven in torotate in the second direction that is opposite to the first direction.

For another example, the first actuator can have a first mating element,the first torque limiting mechanism can have a second mating element,engagement of the first mating element with the second mating elementduring the driving of the first actuator by the motor can define thefirst torque threshold, the second actuator can have a third matingelement, the second torque limiting mechanism can have a fourth matingelement, and engagement of the third mating element with the fourthmating element during the driving of the second actuator by the motorcan define the second torque threshold.

For still another example, the tool driver can include a first shafthaving the first and second actuators and the first and second limitingmechanisms attached thereto along a longitudinal length thereof. In atleast some embodiments, the first motor can be configured to rotate asecond shaft having first and second drive disks attached thereto alonga longitudinal length thereof, the first drive disk can be operativelycoupled to the first actuator such that rotation of the second shaftcauses the first actuator to rotate, and the second drive disk can beoperatively coupled to the second actuator such that rotation of thesecond shaft causes the second actuator to rotate. Additionally oralternatively, in at least some embodiments, the tool driver can includea third actuator attached to the shaft along a longitudinal lengththereof, a second motor configured to drive the third actuator toactuate a third function of the actuator, and a third torque limitingmechanism that sets a third torque threshold for the third actuator. Inat least some embodiments, the first function can be closing of the endeffector at a first speed, the second function can be closing the endeffector at a second speed that is greater than the first speed, and thethird function can be firing of the end effector.

For yet another example, the first motor can include a single motor, andthe tool driver can include one or more additional motors that are eachconfigured to drive one or more additional actuators of the tool driverthat each actuate a function of the end effector that is different fromthe first and second functions.

For another example, the first and second actuators can each include arotatable gear.

In another embodiment, a surgical system is provided that includes asurgical tool including an elongate shaft having an end effector at adistal end thereof, and a tool driver of a robotic surgical system. Thetool driver is configured to releasably couple to the surgical tool. Thetool driver includes a first actuator configured to be actuated to causethe end effector to perform a first function, a second actuatorconfigured to be actuated to cause the end effector to perform a secondfunction, a first motor configured to selectively actuate each of firstand second actuators, a first torque limiting mechanism configured tolimit an amount of torque applied by the motor to the first actuator,and a second torque limiting mechanism configured to limit an amount oftorque applied by the motor to the second actuator.

The surgical system can vary in any number of ways. For example, thefirst motor can be configured to selectively shift between engagementwith the first actuator to drive the first actuator without driving thesecond actuator and engagement with the second actuator to drive thesecond actuator without driving the first actuator. For another example,the first function can be closing of the end effector at a first speed,and the second function can be closing the end effector at a secondspeed that is greater than the first speed. For yet another example, thefirst motor can include a single motor, and the tool driver can includeone or more additional motors that are each configured to drive one ormore additional actuators of the tool driver that are each configured tobe actuated to cause the end effector to perform a function of that isdifferent from the first and second functions.

In another aspect, a surgical method is provided that in one embodimentincludes advancing an end effector of a surgical tool into a body of apatient using a robotic surgical system. The surgical tool is releasablyand replaceably coupled to the robotic surgical system. The surgicalmethod also includes actuating a single motor of the robotic surgicalsystem to drive a first actuator of the robotic surgical system andthereby cause the end effector to execute a first function in the bodyof the patient. The motor has a maximum torque output, and an amount oftorque applied by the motor to the first actuator is prevented fromexceeding a first torque threshold that is less than the maximum torqueoutput. The surgical method also includes actuating the single motor ofthe robotic surgical system to cause the end effector to execute asecond function in the body of the patient that is different from thefirst function. An amount of torque applied by the motor to the secondactuator is prevented from exceeding a second torque threshold that isless than the maximum torque output and that is different from the firsttorque threshold.

The surgical method can vary in any number of ways. For example, theamount of torque applied by the motor to the first actuator can beprevented from exceeding the first torque threshold when the motordrives rotation of the first actuator in a first direction, and theamount of torque applied by the motor to the first actuator when themotor drives rotation of the first actuator in a second direction can beprevented from exceeding a third torque threshold that is different fromthe first torque threshold. The first direction can be opposite to thesecond direction. The amount of torque applied by the motor to thesecond actuator can be prevented from exceeding the second torquethreshold when the motor drives rotation of the second actuator in thefirst direction, and the amount of torque applied by the motor to thesecond actuator when the motor drives rotation of the second actuator inthe second direction can be prevented from exceeding a fourth torquethreshold that is different from the second torque threshold.

For another example, the first function can be closing of the endeffector at a first speed, and the second function can be closing theend effector at a second speed that is greater than the first speed.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of one embodiment of a surgical roboticsystem that includes a patient-side portion and a user-side portion;

FIG. 2 is a perspective view of one embodiment of a robotic arm of asurgical robotic system with a surgical tool releasably and removablycoupled to the robotic arm;

FIG. 3 is a perspective view of a tool driver of the robotic arm of FIG.2;

FIG. 4 is a side view of the surgical tool of FIG. 2 uncoupled from therobotic arm, the tool including a shaft extending from a puck at aproximal end and having an end effector located at a distal end of theshaft;

FIG. 5 is a partial cross-sectional side view of another embodiment of apuck and shaft of a surgical tool;

FIG. 6 is a perspective view of an actuation assembly of the puck ofFIG. 5;

FIG. 7 is a perspective view of a wrist portion of the surgical tool ofFIG. 4;

FIG. 8 is a partial side schematic view of one embodiment of an endeffector having a knife actuation assembly;

FIG. 9 is a perspective view of engaged gears of the puck of FIG. 5;

FIG. 10 is a partial cross-sectional side view of the puck of FIG. 5 ina bailout state;

FIG. 11 is a perspective view of engaged gears of the puck of FIG. 5including a shiftable gear;

FIG. 12 is an exploded partially cross-sectional view of one of thegears of FIG. 11 and a shaft on which the gear is movably attachable;

FIG. 13 is an exploded view of one embodiment of a closure assembly, afiring assembly, and a shifter of a puck;

FIG. 14 is a perspective view of one embodiment of a closure assemblyand a firing assembly;

FIG. 15 is a top view of a quick closure assembly of the closureassembly of FIG. 14;

FIG. 16 is a portion of the quick closure assembly of FIG. 15;

FIG. 17 is a top view of a firm closure assembly of the closure assemblyof FIG. 14;

FIG. 18 is a portion of the firm closure assembly of FIG. 17;

FIG. 19 is a flipped bottom view of the firing assembly of FIG. 14;

FIG. 20 is a portion of the firing assembly of FIG. 19;

FIG. 21 is a graphical representation of terminology associated with sixdegrees of freedom; and

FIG. 22 is a schematic view of one embodiment of a computer system.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

Further, in the present disclosure, like-named components of theembodiments generally have similar features, and thus within aparticular embodiment each feature of each like-named component is notnecessarily fully elaborated upon. Additionally, to the extent thatlinear or circular dimensions are used in the description of thedisclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan easily be determined for any geometric shape. Sizes and shapes ofthe systems and devices, and the components thereof, can depend at leaston the anatomy of the subject in which the systems and devices will beused, the size and shape of components with which the systems anddevices will be used, and the methods and procedures in which thesystems and devices will be used.

Various exemplary methods, systems, and devices for limiting torque inrobotic surgical tools are provided. In general, a surgical tool can beconfigured to releasably and removably couple to a robotic surgicalsystem. The robotic surgical system can include a motor configured toprovide torque to the surgical tool to drive two different functions ofthe surgical tool. The two different functions can be functions that arenot performed at the same time, e.g., the functions can be mutuallyexclusive. The motor can thus be configured to selectively drive one oftwo functions of the surgical tool, which may allow the surgical tool toperform more functions than traditional surgical tools since one motorcan be configured to drive two different functions of the surgical toolinstead of just one function of the surgical tool. The surgical tool caninclude two torque limiting mechanisms, each associated with the motor,each associated with one of the functions, and each configured to limitan amount of the torque from the motor that drives the functionassociated therewith. The torque limiting mechanisms may thus preventthe motor from providing too much torque to the surgical tool. If toomuch torque is provided to the surgical tool, the function may not beeffected as desired and/or damage may be caused to the surgical tooland/or to the patient on which the surgical tool is being used. Thetorque limiting mechanisms may serve as a backup safety mechanism to therobotic surgical system in the event that the robotic surgical systemdoes not appropriately limit torque output of the motor according to itscontrol programming, which may happen for any number of reasons, such asinadvertent system malfunction or electrical control signals beingprocessed too slowly or too quickly to effect desired torque output ofthe motor. The torque limiting mechanisms can be mechanical members soas to not be reliant on electrical control signals to effect torquelimiting.

The robotic surgical system can include one or more motors in additionto the one motor configured to drive the two different functions. Eachof the additional one or more motors can be configured to drive afunction of the surgical tool that is different from each of the otherfunctions of the surgical tool. The robotic surgical system may thus beconfigured to drive at least three different functions of the surgicaltool, which may allow for more versatile use of the surgical tool in abody of a patient and/or allow two or more of the functions to beperformed at the same time since the two or more functions can besimultaneously, respectively driven by two or more of the motors.

Functions of the surgical tool can include a function of an end effectorof the surgical tool. Functions of the end effector can include, forexample, a quick close of the end effector (e.g., closing jaws of thesurgical tool at a first speed), a slower close of the end effector(e.g., closing jaws of the surgical tool at a second speed that is lessthan the first speed associated with quick close), articulation of theend effector relative to an elongate shaft of the surgical tool (e.g.,angling the end effector relative to a longitudinal axis of the elongateshaft), rotation of the end effector relative to the elongate shaft(e.g., rotation of the end effector about a longitudinal axis thereof),and rotation of the end effector and the shaft as a unit about thelongitudinal axis of the shaft. In an exemplary embodiment, the twodifferent functions configured to be driven by the one motor include thequick close of the end effector and the slower close of the endeffector. Quick close and slower close may thus be prevented from beingdriven at the same time since the one motor will be shifted to driveonly one or the other. Providing torque limiting mechanisms for each ofthe quick close and slower close functions may allow for the same motorto drive both functions while providing a different amount of maximumtorque to the surgical tool to drive each of the functions and therebyallow the two different closure functions to be performed properly.

Robotic Surgical Systems

The systems, devices, and methods disclosed herein can be implementedusing a robotic surgical system.

As will be appreciated by a person skilled in the art, electroniccommunication between various components of a robotic surgical systemcan be wired or wireless. A person skilled in the art will alsoappreciate that all electronic communication in the system can be wired,all electronic communication in the system can be wireless, or someportions of the system can be in wired communication and other portionsof the system can be in wireless communication.

FIG. 1 is a perspective view of one embodiment of a surgical roboticsystem 300 that includes a patient-side portion 310 that is positionedadjacent to a patient 312, and a user-side portion 311 that is located adistance from the patient, either in the same room and/or in a remotelocation. The patient-side portion 310 generally includes one or morerobotic arms 320 and one or more tool assemblies 330 that are configuredto releasably couple to a robotic arm 320. The user-side portion 311generally includes a vision system 313 for viewing the patient 312and/or surgical site, and a control system 315 for controlling themovement of the robotic arms 320 and each tool assembly 330 during asurgical procedure.

The control system 315 can have a variety of configurations and can belocated adjacent to the patient, e.g., in the operating room, remotefrom the patient, e.g., in a separate control room, or the controlsystem 315 can be distributed at two or more locations. For example, adedicated system control console can be located in the operating room,and a separate console can be located in a remote location. The controlsystem 315 can include components that enable a user to view a surgicalsite of a patient 312 being operated on by the patient-side portion 310and/or to control one or more parts of the patient-side portion 310(e.g., to perform a surgical procedure at the surgical site 312). Insome embodiments, the control system 315 can also include one or moremanually-operated input devices, such as a joystick, exoskeletal glove,a powered and gravity-compensated manipulator, or the like. These inputdevices can control teleoperated motors which, in turn, control themovement of the surgical system, including the robotic arms 320 and toolassemblies 330.

The patient-side portion can also have a variety of configurations. Asdepicted in FIG. 1, the patient-side portion 310 can couple to anoperating table 314. However, in some embodiments, the patient-sideportion 310 can be mounted to a wall, to the ceiling, to the floor, orto other operating room equipment. Further, while the patient-sideportion 310 is shown as including two robotic arms 320, more or fewerrobotic arms 320 may be included. Furthermore, the patient-side portion310 can include separate robotic arms 320 mounted in various positions,such as relative to the surgical table 314 (as shown in FIG. 1).Alternatively, the patient-side portion 310 can include a singleassembly that includes one or more robotic arms 320 extending therefrom.

FIG. 2 illustrates one embodiment of a robotic arm 420 and a toolassembly 430 releasably coupled to the robotic arm 420. The robotic arm420 can support and move the associated tool assembly 430 along one ormore mechanical degrees of freedom (e.g., all six Cartesian degrees offreedom, five or fewer Cartesian degrees of freedom, etc.).

The robotic arm 420 can include a tool driver 440 at a distal end of therobotic arm 420, which can assist with controlling features associatedwith the tool assembly 430. The robotic arm 420 can also include anentry guide 432 (e.g., a cannula mount or cannula) that can be a part ofor removably coupled to the robotic arm 420, as shown in FIG. 2. A shaft436 of the tool assembly 430 can be inserted through the entry guide 430for insertion into a patient.

In order to provide a sterile operation area while using the surgicalsystem, a barrier 434 can be placed between the actuating portion of thesurgical system (e.g., the robotic arm 420) and the surgical instruments(e.g., the tool assembly 430). A sterile component, such as aninstrument sterile adapter (ISA), can also be placed at the connectinginterface between the tool assembly 430 and the robotic arm 420. Theplacement of an ISA between the tool assembly 430 and the robotic arm420 can ensure a sterile coupling point for the tool assembly 430 andthe robotic arm 420. This permits removal of tool assemblies 430 fromthe robotic arm 420 to exchange with other tool assemblies 430 duringthe course of a surgery without compromising the sterile surgical field.

FIG. 3 illustrates the tool driver 440 in more detail. As shown, thetool driver 440 includes one or more motors, e.g., five motors 442 areshown, that control a variety of movements and actions associated withthe tool assembly 430, as will be described in greater detail below. Forexample, each motor 442 can couple to and/or interact with an activationfeature (e.g., gear) associated with the tool assembly 430 forcontrolling one or more actions and movements that can be performed bythe tool assembly 430, such as for assisting with performing a surgicaloperation. The motors 442 are accessible on the upper surface of thetool driver 440, and thus the tool assembly is configured to mount ontop of the tool driver 440 to couple thereto. The tool driver 440 alsoincludes a shaft-receiving channel 444 formed in a sidewall thereof forreceiving the shaft of the tool assembly 430. In other embodiments, theshaft can extend through on opening in the tool driver 440, or the twocomponents can mate in various other configurations.

FIG. 4 illustrates the tool assembly 430 uncoupled from the robotic arm420. The tool assembly 430 includes a housing or puck 435 coupled to aproximal end of the shaft 436 and an end effector 438 coupled to adistal end of the shaft 436. The puck 435 can include coupling featuresthat assist with releasably coupling the puck 435 to the tool driver 440of the robotic arm 420. The puck 435 can include gears and/or actuatorsthat can be actuated by the one or more motors 442 in the driver 440, aswill be described in greater detail below. The gears and/or actuators inthe puck 435 can control the operation of various features associatedwith the end effector 438 (e.g., clamping, firing, rotation,articulation, energy delivery, etc.), as well as control the movement ofthe shaft 436 (e.g., rotation of the shaft).

The shaft 436 can be fixed to the puck 435, or it can be releasablycoupled to the puck 435 such that the shaft 436 can be interchangeablewith other shafts. This can allow a single puck 435 to be adaptable tovarious shafts 436 having different end effectors 438. The shaft 436 caninclude actuators and connectors that extend along the shaft and assistwith controlling the actuation and/or movement of the end effector 438and/or shaft 436. The shaft 436 can also include one or more joints orwrists 437 that allow a part of the shaft 436 or the end effector 438 toarticulate relative to the longitudinal axis of the shaft 436. This canallow for fine movements and various angulation of the end effector 438relative to the longitudinal axis of the shaft 436. The end effector 438can include any of a variety of surgical tools, such as a stapler, aclip applier, forceps, a needle driver, a cautery device, a cuttingtool, a pair of jaws, an imaging device (e.g., an endoscope orultrasound probe), or a combined device that includes a combination oftwo or more various tools.

FIG. 5 illustrates an embodiment of a puck 735 and a proximal end of ashaft 736 extending from the puck 735. As shown in FIG. 5, the puck 735includes a plurality of actuation gears and gear shafts that can beeither directly or indirectly controlled by any one of the motors 442associated with the driver 440. For example, as shown in FIG. 5, thepuck 735 is configured to couple to five motors at the locationsindicated by reference numbers M1, M2, M3, M4, and M5. In thisembodiment, the puck 735 includes first and second articulation gearsG1, G2 that are coupled respectively to the first and second motors M1,M2 via a series of one or more additional gears and shafts. Actuation ofthe first and second motors M1, M2 will rotate the articulation gearsG1, G2, which in turn cause linear movement of an articulation cable ina proximal or distal direction to thereby cause articulation of an endeffector at a distal end of the shaft 736 in desired left and rightdirections. The puck 735 also includes a shaft rotation gear G3 a thatis coupled to the third motor M3 via a series of one or more additionalgears and shafts. Actuation of the third motor M3 will thus rotate theshaft rotation gear G3 a, thereby causing rotation of the shaft 736. Thethird motor M3 can also be configured to shift and to couple, via aseries of one or more additional gears and shafts, to a head rotationgear G3 b, which will cause rotation of the end effector relative to theshaft 736. The puck 735 further includes a firm close gear G4 a that iscoupled to the fourth motor M4 via a series of one or more additionalgears and shafts. Actuation of the fourth motor M4 will rotate the firmclose gear G4 a to cause linear translation of a drive screw to firmlyclose the jaws of the end effector. The puck 735 further includes aquick close gear G4 b that can also couple to the fourth motor M4 via aseries of one or more additional gears and shafts. When the fourth motorM4 is shifted into engagement with the quick close gear G4 bh, actuationof the fourth motor M4 will rotate the quick close gear G4 b to causelinear translation of a quick close cable to quickly close the jaws ofthe end effector. Finally, the illustrated puck 735 includes a firinggear G5 that is coupled to the fifth motor M5 via a series of one ormore additional gears and shafts. Actuation of the fifth motor M5 willrotate the firing gear G5, thereby driving a lead screw linearly toadvance a sled through the end effector, as will be discussed in moredetail below.

FIG. 6 illustrates actuation assembly 870 components of the puck of FIG.5. As shown and indicated above, each of the gears G1, G2, G3, G4. G5 iscoupled to an actuation shaft that extends from the actuation assembly870 and along the shaft 736 of the tool assembly, such as forcontrolling the movements of the end effector. FIG. 7 illustrates adistal end of the actuation shafts extending from a wrist 980 locatedjust proximal of the end effector. The wrist 980 can allow for finemovements and angulation of the end effector relative to the proximalend of the shaft 436. As shown in FIG. 7, the wrist 980 includes fourarticulation cables 982 that are spaced around a perimeter of the wrist980. When actuated (e.g., pushed, pulled, rotated), the articulationcables 982 will cause articulation of the end effector (e.g., movementup, down, left, right, and combinations thereof) relative to theproximal end of the shaft 736. The articulation cables 982 are connectedto articulation couplers 839, shown in FIG. 6, that are drivenproximally and distally when the articulation gears G1, G2 are actuatedby the first and second motors M1, M2. The wrist 980 also includes anupper rotary driver 984 that when actuated can cause the pair of jaws ofthe end effector to firmly close. The upper rotary driver 984 is coupledto the firm close gear G4 a shown in FIGS. 5 and 6 such that rotation ofthe firm close gear G4 a by the fourth motor M4 causes rotation of therotary driver 984. The wrist 980 can also include a lower rotary driver986 that when actuated can cause movement of a sled located at the endeffector. The lower rotary driver 986 is coupled to the firing gear G5shown in FIG. 6 and it likewise rotates in response to rotation of thefiring gear G5. The illustrated wrist 980 further includes a linear pullcable 988 that is coupled to the quick close gear G4 b shown in FIGS. 5and 6 and that moves linearly in a proximal direction to cause rapidclose of the pair of jaws of the end effector.

FIG. 8 illustrates a portion of an end effector 1038 having a knifeactuation assembly 1080 that includes a drive member 1082, a knife 1084,a knife sled 1086, and a lead screw or rotary driver 986. The drivemember 1082 includes internal threads that are threadably coupled withthe rotary driver 986. Such coupling can allow drive member 1082 to movealong the rotary driver 986 when the rotary driver 986 is rotated. Asdiscussed above, the rotary driver 986 can be actuated at the wrist 980,as shown in FIG. 7, thereby causing rotation of the rotary driver 986and linear movement of the knife sled 1086 along the rotary driver 986.The rotary driver 986 is coupled to the firing gear G5 shown in FIGS. 5and 6. The knife actuation assembly 1080 is configured to orient theknife 1084 in a cutting position when the drive member 1082 pushes theknife sled 1086 along the rotary driver 986 and to stow the knife 1084when the drive member 1082 is moved proximally relative to the knifesled 1086. In operation, the rotary driver 986 is first rotated toadvance the drive member 1082 distally along the rotary driver 986thereby pushing the knife sled 1086 in the distal direction andangularly orienting the knife 1084 in the cutting position. At the endof the distal movement of the assembly 1080, the direction of rotationof the rotary driver 986 is reversed to retract the drive member 1082proximally relative to the knife sled 1086, thereby causing the knife1084 to rotate down into the stowed position, such as via interactionbetween an interface feature 1092 and the knife 1084.

Two embodiments of bailout mechanisms are disposed in the puck 735 ofFIG. 5 and are configured to engage, drive, reverse, and/or otherwiseaffect the actuation assembly 870 of FIG. 6. As illustrated in FIG. 5, acrank arm 2000 is disposed externally to an inner cover 735 i of thepuck 735 but inside of an outer cover 735 c of the puck 735. The crankarm 2000 is disposed on a shaft 2002 extending through a hole in theinner cover 735 i, and the crank arm 2000 is configured to pivot aboutthe shaft 2002. The shaft 2002 is configured to be longitudinallyslidable relative to the crank arm 2000, and has a button 2004 on aproximal end thereof. The button 2004 is configured to be manuallypushed distally and is configured to couple onto the crank arm 2000through various means, for example pins, tabs, hooks, etc., such thatpivoting of the crank arm 2000 will rotate the button 2004 and thus theshaft 2002. The shaft 2002 has a one-way gear 2006 on a distal endthereof. The one-way gear 2006 has a circular shape with teeth 2006 textending distally from a distal surface thereon. The teeth 2006 t areshaped such that they can engage corresponding teeth and apply arotation force in one direction only, as illustrated in FIG. 9. Theshaft 2002 is displaced longitudinally proximal to a drive shaft 2020,which has spur gears G5 a and G4 al fixed thereon. The spur gear G5 a isrotatably coupled in a gear train with gears G5 b and G5 c, terminatingin the firing gear G5. The spur gear G5 a has teeth T1 extendingproximally from a proximal surface thereon. The teeth T1 correspond insize and shape to the teeth 2006 t and are configured to engage theteeth 2006 t and receive a rotation force in one direction only. Thespur gear G4 al is rotatably coupled in a gear train with gears G4 a 2and G4 a 3, terminating in the firm close gear G4 a. The drive shaft2020 is displaced longitudinally proximal to the third motor M3, and isrotatable free of the third motor M3.

A threaded shaft 2030 is disposed laterally from the drive shaft 2020and is disposed longitudinally proximal to the motors M4, M5. A firstend 2030 a of the threaded shaft 2030 passes through a housing 2032 thatis disposed on a shaft 2034 such that the threaded shaft 2030 isrotatable about its longitudinal axis relative to the housing 2032. Theshaft 2034 has a series of gears fixed thereto and one or moreadditional gears and shafts engageably coupled to the series of gearsand the shaft 2034 that engage the motors M4, M5. As motors M4, M5 aredriven, the series of gears on the shaft 2034 are part of gear trainsthat engage and rotate the spur gear G5 a and the spur gear G4 al andultimately the firing gear G5 and the firm close gear G4 a. A second end2030 b of the threaded shaft 2030 passes through a displacement nut2036, through a hole in the inner cover 735 i, and through a bailoutbolt 2038. The bailout bolt 2038 rests just outside of the inner cover735 i and is fixedly attached to the threaded shaft 2030 such thatrotation of the bailout bolt 2038 rotates the threaded shaft 2030. Thedisplacement nut 2036 is inside the housing 2032 and is rotatable on thethreaded shaft 2030. First and second rods 2040 a, 2040 b (e.g., rigidrods such as metal rods) are pivotally fixed to the displacement nut2036 on a proximal and distal side, respectively, in any of a variety ofdifferent ways, such as using pivot pins, embedding ends of the rods2040 a, 2040 b therein, etc. The first and second rods 2040 a, 2040 bextend proximally and distally, respectively, from the displacement nut2036 and fixedly terminate on first and second gear assemblies 2042 a,2042 b (e.g., on first and second washers 2041 a, 2041 b thereof),respectively, that are both part of the gear series on the shaft 2034and are longitudinally slidable on the shaft 2034. The first gearassembly 2042 a couples through gear trains and shafts to the fifthmotor M5 and is part of the gear train that rotates the firing gear G5.The second gear assembly 2042 b couples through gear trains and shaftsto the fourth motor M4 and is part of the gear train that rotates thefirm close gear G4 a. The first and second rods 2040 a, 2040 b can bepivotally fixed to the first and second gear assemblies 2042 a, 2042 bin any of a variety of ways, such as by pivot pins, embedding ends ofthe rods 2040 a, 2040 b therein, etc.

During normal operation as illustrated in FIG. 5, the gear assemblies2042 a, 2042 b remain engaged in the gear trains connecting the motorsM4, M5 to the firm close gear G4 a and the firing gear G5, respectively.The motors M4, M5 can cause rotation of the firm close gear G4 a and thefiring gear G5 as explained above. The displacement nut 2036 rests at aninner edge of the inner cover 735 i directly opposite the bailout bolt2038 placed on the outside of the inner cover 735 i. The threaded shaft2030 does not rotate. The shaft 2002 remains in a proximal position,keeping the one-way gear 2006 disengaged from any surrounding gears andthe button 2004 proximal to the crank arm 2000 and the inner cover 735i. The shaft 2002 is kept in a proximal position through frictioninteraction with the hole in the inner cover 735 i through which theshaft 2002 passes, but the shaft 2002 can be kept proximal in any of avariety of ways, such as by a spring disposed around the shaft 2002between the crank arm 2000 and the button 2004 that will bias the shaft2002 and the button 2004 proximally, etc. The crank arm 2000 isimmobile. The outer cover 735 c covers all components that are externalto the inner cover 735 i.

When bailout is desired, such as when a malfunction occurs in the endeffector in the firing and/or firm close functions, the outer cover 735c can be removed. A user can manually rotate the bailout bolt 2038,which will cause rotation of the threaded shaft 2030 because the bailoutbolt 2038 is fixed on the threaded shaft 2030. As the threaded shaft2030 rotates, the displacement nut 2036 will translate along thethreaded shaft 2030 toward the housing 2032 because the displacement nut2036 is rotatably placed on the threaded shaft 2030. Movement of thedisplacement nut 2036 will cause the metal rods 2040 a, 2040 b to pivoton the displacement nut 2036 and the gear assemblies 2042 a, 2042 b andforce the gear assemblies 2042 a, 2042 b to move proximally anddistally, respectively, on the shaft 2034 because the metal rods 2040 a,2040 b will apply proximal and distal force to the gear assemblies 2042a, 2042 b, respectively, as the metal rods 2040 a, 2040 b move towardthe housing 2032 (and consequently toward the shaft 2034) with thedisplacement nut 2036. As the gear assemblies 2042 a, 2042 b moveproximally and distally, respectively, the gear assemblies 2042 a, 2042b will move out of engagement with the gear trains that engage themotors M4, M5 to the firm close gear G4 a and the firing gear G5. Asillustrated in FIG. 10, the gear assemblies 2042 a, 2042 b will moveentirely out of engagement, thus severing any engagement between themotors M4, M5 and the gears G4 a, G5. When the gear assemblies 2042 a,2042 b have moved out of engagement of the gear trains, any actuation ofthe motors M4, M5 will have no effect on the actuation assembly 870. Thebutton 2004 can then be manually pushed distally by a user, which willcause the shaft 2002 to move distally. The button 2004 will couple tothe crank arm 2000, and the teeth 2006 t on the one-way gear 2006 willengage the teeth T1 on the spur gear G5 a. The crank arm 2000 can thenbe pivoted by a user to rotate the spur gear G5 a, the shaft 2020, andthe spur gear G4 al together because they are all fixed to one another.The crank arm 2000 can be rotated, which causes rotation of the geartrains containing gears G5 a, G5 b, G5 c, and G5 and gears G4 al, G4 a2, G4 a 3, and G4 a. The teeth 2006 t, T1 only allow engagement androtation in one direction, thus ensuring that rotation of the crank arm2000 causes retraction and bailout of the firing and firm closefunctions.

In at least some embodiments, a hollow outer shaft 2044 extends aroundthe shaft 2034 and rests distal to the gear assembly 2042 b. The outershaft 2044 is longitudinally slidable around the shaft 2034 and has oneor more tabs 2044 t on a distal end thereof that flare proximally. Achannel 2046 sized to receive the shaft 2044 extends through a distalend of the puck 735. During normal operation, the outer shaft 2044remains at rest, and the tabs 2044 t remain inside the puck 735 andflare out to engage edges of the channel 2046 and prevent the outershaft 2044 from sliding through the channel 2046. During bailout as thegear assembly 2042 b is forced distally as described above, the gearassembly 2042 b contacts a proximal end of the outer shaft 2044 andbegins to force the outer shaft 2044 distally with continued movement ofthe gear assembly 2042 b. As the outer shaft 2044 is forced distally,the tabs 2044 t are forced into the channel 2046 and begin to compressbecause of their proximal flared shape, allowing the tabs 2044 t and theouter shaft 2044 to enter the channel 2046. When the gear assembly 2042b is in its distal-most position, the tabs 2044 t will pass entirelythrough the channel 2046, and the tabs 2044 t and a distal end of theouter shaft 2044 will be positioned outside the puck 735, as illustratedin FIG. 10. Because of the proximal flared shape of the tabs 2044 t, thetabs 2044 t will engage an outer surface of the puck 735 and prevent theouter shaft 2044 from being moved entirely back into the puck 735.Protuberance of the outer shaft 2044 prevents the puck 735 from beingcorrectly reengaged with the tool driver 440, which will prevent thepuck 735 from being used again in a future operation after a bailout wasrequired. Faulty pucks may be prevented from being used again throughthis mechanism.

Another bailout mechanism is illustrated in FIGS. 5 and 10 in the formof a tool receiver 2050. The tool receiver 2050 is configured to receivea tool, such as a hex wrench, and is displaced longitudinally proximalto the actuation assembly 870. The tool receiver 2050 is fixedlyattached to a shaft 2050 s that is rotatably engaged with the upper andlower rotary drivers 984, 986 through gear engagements inside of theactuation assembly 870. The tool receiver 2050 extends through the innercover 735 i. During normal operation, the tool receiver 2050 rotateswith the actuation assembly 870 and is covered by the outer cover 735 c.When bailout is desired, such as when a malfunction occurs in the endeffector in the firing and/or firm close functions, the outer cover 735c can be removed, and a user can manually insert a tool such as a hexwrench into the tool receiver 2050 configured to receive such a tool.The user can then rotate the tool, which causes direct application ofrotational force to the shaft 2050 s and the upper and lower rotarydrivers 984, 986. The user can reverse and/or retract the firing andfirm close functions by continued rotation of the tool.

As mentioned above, the fourth motor M4 is configured to be shiftedbetween operative engagement with the firm close gear G4 a to effectfirm closure of the end effector and the quick close gear G4 b to effectquick closure of the end effector. As also mentioned above, the spurgear G4 al is rotatably coupled in a gear train with gears G4 a 2 and G4a 3, terminating in the firm close gear G4 a. The spur gear G4 al can berotatably coupled in another gear train with gears G4 a 2 and G4 a 3,terminating in the quick close gear G4 b. Shiftable gear G4 a 3 isconfigured to shift the fourth motor M4 by moving between these two geartrains for the quick close gear G4 b and the firm close gear G4 a. Inother words, movement of the shiftable gear G4 a 3 between a firstposition, in which the shiftable gear G4 a 3 is in the gear train forthe firm close gear G4 a, and a second position, in which the shiftablegear G4 a 3 is in the gear train for the quick close gear G4 b, causesthe fourth motor M4 to shift between driving firm close of the endeffector (when the shiftable gear G4 a 3 is in the first position) andquick close of the end effector (when the shiftable gear G4 a 3 is inthe second position). Thus, only one of the two gear trains for quickclose and firm close can be active at one time for the fourth motor M4to drive. The shiftable gear G4 a 3 is slidably mounted on a shaft 2031along which the shiftable gear G4 a 3 slides when moving between thefirst and second positions. FIGS. 5 and 10 illustrate the shiftable gearG4 a 3 in solid line in the first position and the shiftable gear G4 a 3in phantom (dotted line) in the second position. FIG. 11 illustrates theshiftable gear G4 a 3 in phantom in the first position and the shiftablegear G4 a 3 in solid line in the second position. The first position ofthe shiftable gear G4 a 3 is the default position of the shiftable gearG4 a 3. In this way, regular, faster closure of the end effector is thedefault mode of closure.

In both of the first and second positions, the shiftable gear G4 a 3 isengaged with spool gear G4 a 2, as shown in FIGS. 5 and 11. In the firstposition, the shiftable gear G4 a 3 is engaged with a lower gear LG ofthe spool gear G4 a 2. In the second position, the shiftable gear G4 a 3is engaged with an upper gear UG of the spool gear G4 a 2.

As shown in FIGS. 5 and 11, the puck 435 includes an electromagnet 2029configured to be selectively actuated to shift the fourth motor M4 bymoving the shiftable gear G4 a 3 between the first and second positions.The electromagnet 2029 as shown is in the form of a solenoid. Theelectromagnet 2029 is configured to be selectively actuated to generatea magnetic field within operative range of the shiftable gear G4 a 3.When the electromagnet 2029 is not generating the magnetic field, theshiftable gear G4 a 3 is in the first position. When the electromagnet2029 is generating the magnetic field, the magnetic effect draws theshiftable gear G4 a 3 toward the electromagnet 2029 to move theshiftable gear G4 a 3 from the first position to the second position,e.g., to cause the shiftable gear G4 a 3 to slide up the shaft 2031. Theshiftable gear G4 a 3 is thus made at least partially from a metal orother material configured to be affected by the magnetic field so as toallow the shiftable gear G4 a 3 to be drawn toward the electromagnet2029. Removal of the electromagnetic field allows the shiftable gear G4a 3 to move from the second position to the first position, e.g., toslide down the shaft 2031.

The electromagnet 2029 can be actuated in any of a variety of ways togenerate the magnetic field. For example, the electromagnet 2029 can beconfigured to be operatively engaged with a current source in the tooldriver (or elsewhere in the robotic surgical system of which the tooldriver is a part) to which the puck 735 is releasably coupled, such asby a wire extending from the electromagnet 2029 to a coupling on thepuck 735 that engages a corresponding coupling on the tool driver. Therobotic surgical system's current source can be activated to actuate theelectromagnet 2029. The robotic surgical system's current source can beactivated in any number of ways, as will be appreciated by a personskilled in the art, such as by a user providing an input to an inputtool of the robotic surgical system. For another example, theelectromagnet 2029 can be configured to be electrically activated toalternately push and pull an actuation rod that is operatively coupledto the shiftable gear G4 a 3. When the electromagnet 2029 is inactive,the shiftable gear G4 a 3 is in the first position with the actuationrod located inside the electromagnet 2029. When the electromagnet 2029is electrically activated, the actuation rod is pushed outward andadvances the shiftable gear G4 a 3 to the second position.

One electromagnet 2029 is used in this illustrated embodiment to movethe shiftable gear G4 a 3, but more than one electromagnet can be usedto move the shiftable gear G4 a 3 or any of the other shiftable gearsdescribed herein. Using more than one electromagnet can allow a greatforce to be generated, which may facilitate movement of larger gearsand/or help ensure gear movement.

FIG. 11 and FIG. 12 illustrate gear supports 2035 for the quick closegear G4 b. The gear supports 2035 are configured to maintain verticalposition of the quick close gear G4 b along a shaft 2037 to which thequick close gear G4 b is mounted while allowing rotation of the quickclose gear G4 b about the shaft 2037. The quick close gear G4 b beingmaintained in a vertical position may facilitate engagement of the quickclose gear G4 b with the shiftable gear G4 a 3 since the quick closegear G4 b will be located in a predictable vertical location forengagement with the shiftable gear G4 a 3 when the shiftable gear G4 a 3moves to its second position. Two gear supports 2035 are shown, butanother number of gear supports 2035 may be used. Additionally, any ofthe non-shiftable gears described herein that are rotatably mounted on ashaft can be coupled to at least one gear support configured to maintainvertical position of the gear to help ensure engagement of the gear withthe one or more other gears engaged therewith.

As mentioned above, the third motor M3 is configured to be shiftedbetween operative engagement with the shaft rotation gear G3 a to effectcausing rotation of the shaft 736 of the tool assembly and the headrotation gear G3 b to effect rotation of the end effector relative tothe shaft 736. As shown in FIG. 5, a gear G3 is rotatably coupled in agear train with gears G3 al and G3 a 2, terminating in the shaftrotation gear G3 a. The gear G3 can be rotatably coupled in another geartrain with gears G3 al and G3 a 3, terminating in the head rotation gearG3 b. Shiftable gear G3 al is configured to shift the third motor M3 bymoving between these two gear trains for the shaft rotation gear G3 aand the head rotation gear G3 b. In other words, movement of theshiftable gear G3 al between a first position, in which the shiftablegear G3 al is in the gear train for the shaft rotation gear G3 a, and asecond position, in which the shiftable gear G3 al is in the gear trainfor the head rotation gear G3 b, causes the third motor M3 to shiftbetween driving rotation of the end effector (when the shiftable gear G3al is in the first position) and rotation of the shaft 736 and the endeffector (when the shiftable gear G3 al is in the second position).Thus, only one of the two gear trains for end effector rotation can beactive at one time for the third motor M3 to drive. In both of the firstand second positions, the shiftable gear G3 al is engaged with gear G3,as shown in FIGS. 5 and 10. The shiftable gear G3 al is slidably mountedon a shaft 2033 along which the shiftable gear G3 al slides when movingbetween the first and second positions. FIGS. 5 and 10 illustrate theshiftable gear G3 al in solid line in the first position, and FIG. 5illustrates the shiftable gear G3 al in phantom (dotted line) in thesecond position. The first position of the shiftable gear G3 al is thedefault position of the shiftable gear G3 al. In this way, rotation ofthe end effector relative to the shaft 736 is the default mode of endeffector rotation.

As shown in FIGS. 5 and 10, the puck 735 includes an electromagnet 2035configured to be selectively actuated to shift the third motor M3 bymoving the shiftable gear G3 al between the first and second positions.The electromagnet 2035 as shown is in the form of a solenoid and can beconfigured to be activated and deactivated to move the shiftable gear G3al similar to the electromagnet 2029 discussed above that can beactivated and deactivated to move the shiftable gear G4 a 3. Theshiftable gear G3 al is thus made at least partially from a metal orother material configured to be affected by the magnetic field so as toallow the shiftable gear G3 al to be drawn toward the electromagnet2035.

As illustrated in FIG. 13, the puck 735 can include a closure assembly2052 configured to limit an amount of torque provided to the toolassembly 430 by the fourth motor M4 for effecting closure of the endeffector. The closure assembly 2052 is part of the second gear assembly2042 b (see FIGS. 5 and 10). The closure assembly 2052 is effective tolimit the torque for both firm closure of the end effector and quickclosure of the end effector.

The closure assembly 2052 includes a first gear 2054, a second gear2056, and a coupler 2058 configured to limit an amount of torqueprovided to the tool assembly 430 by the fourth motor M4 when the secondgear assembly 2042 b is driven in a first direction (e.g., driven by thefourth motor M4 to rotate clockwise) and to limit an amount of torqueprovided to the tool assembly 430 by the fourth motor M4 when the secondgear assembly 2042 b is driven in a second, opposite direction (e.g.,driven by the fourth motor M4 to rotate counterclockwise). The secondgear assembly 2042 b is driven by the fourth motor M4 for quick closureand for firm closure, so the closure assembly 2052 is configured tolimit torque for both faster closure of the end effector effected usingthe quick close gear G4 b and slower closure of the end effectoreffected using the firm close gear G4 a. The coupler 2058 is disposedbetween the first and second gears 2054, 2056. A washer 2060 that isalso part of the second gear assembly 2042 b is disposed below thesecond gear 2056 to help with load distribution.

The coupler 2058 and the first and second gears 2054, 2056 can each bemade from any a variety of materials. In an exemplary embodiment, thecoupler 2058 can be plastic, and each of the first and second gears2054, 2056 can be metal.

The first gear 2054 has an inner opening 2056 i extending therethroughthrough which the shaft 2034 extends. The coupler 2058 has one or moreprotrusions 2058 p extending radially outward from an outer perimeterthereof. The inner opening 2056 i of the first gear 2054 is defined by aperimeter 2056 p that has a shape configured to operatively engage theone or more protrusions 2058 p to limit torque provided by the fourthmotor M4 to the firm close and quick close gears G4 a. G4 b. Theperimeter 2056 p defines four lobes that correspond to the fourprotrusions 2058 p of the coupler 2058. The coupler 2058 isnon-rotatably attached to the shaft 2034. When the fourth motor M4 isactuated to drive rotation of a gear 2062 (see FIGS. 5 and 10)operatively coupled to the fourth motor M4 and thereby cause rotation ofthe gear train associated with the one of the firm close gear G4 a andquick close gear G4 b that is currently active (based on the position ofthe shiftable gear G4 a 3), the first and second gears 2054, 2056rotate. The coupler 2058 does not rotate. The first and second gears2054, 2056 are free to rotate in a counterclockwise direction (shown byarrow R2 in FIG. 13) without engaging the protrusions 2058 p. Torque isthus not limited by the closure assembly 2052 when the fourth motor M4drives counterclockwise rotation, which is associated with “backward”movement (e.g., end effector opening), thereby allowing for fastercorrection of, e.g., jaw closure on unintended tissue or on an improperamount of tissue. The perimeter 2054 p defines a stop surface for eachof the protrusions 2058 p such that when the first and second gears2054, 2056 rotate in a clockwise direction (shown by arrow R1 in FIG.13), the protrusions 2058 p will each abut their respective stopsurfaces at a certain point during the gears' rotation. Torque providedby the fourth motor M4 will thus stop being provided to the one of thefirm close gear G4 a and quick close gear G4 b that is currently active.The closure assembly 2052 is thus configured to limit torque. Clockwiserotation of the first and second gears 2054, 2056 is associated with“forward” movement (e.g., end effector closing), thereby allowing forclosure to stop at a certain point so matter (e.g., tissue) clamped bythe end effector is not overly compressed and/or so the end effector isnot damaged by urging the jaws too much together.

The second gear 2056 is the same as the first gear 2054 and has asimilar inner opening 2056 i that has the shaft 2034 extendingtherethrough and that has a perimeter configured to operatively engagethe protrusions 2058 p of the coupler 2058.

As also illustrated in FIG. 13, the puck 735 can include a firingassembly 2064 configured to limit an amount of torque provided to thetool assembly 430 by the fifth motor M5 for effecting firing of the endeffector. The firing assembly 2064 is part of the first gear assembly2042 a (see FIGS. 5 and 10). The firing assembly 2064 is effective tolimit the torque for firing of the end effector. Although the puck 735includes both the firing assembly 2064 and the closure assembly 2052, apuck can include only one of the firing assembly 2064 and the closureassembly 2052.

The firing assembly 2064 includes a first gear 2066, a second gear 2068,and a coupler 2070 configured to limit an amount of torque provided tothe tool assembly 430 by the fifth motor M5 when the first gear assembly2042 a is driven in a first direction (e.g., driven by the fifth motorM5 to rotate clockwise) and to limit an amount of torque provided to thetool assembly 430 by the fifth motor M5 when the first gear assembly2042 a is driven in a second, opposite direction (e.g., driven by thefifth motor M5 to rotate counterclockwise). The coupler 2070 is disposedbetween the first and second gears 2066, 2068. A washer 2072 that isalso part of the first gear assembly 2042 a is disposed above the firstgear 2066 to help with load distribution.

The coupler 2070 of the firing assembly 2064 is generally configured andused similar to the coupler 2058 of the closure assembly 2052, and thefirst and second gears 2066, 2068 of the firing assembly 2064 aregenerally configured and used similar to the first and second gears2054, 2056 of the closure assembly 2052. Inner openings 2064 i, 2066 iof the first and second gears 2066, 2068 are configured to cooperatewith the coupler 2070 to provide torque limits when the fifth motor M5drives clockwise and counterclockwise rotation. Perimeters 2066 p, 2068p of the first and second gears 2066, 2068 define stop surfaces for eachof clockwise and counterclockwise rotation such that, unlike thatdiscussed above regarding the closure assembly 2052, the firing assembly2064 is configured to provide torque limits regardless of a directionthat the fifth motor M5 drives gear rotation. The torque limits are thesame in both the clockwise and counterclockwise directions, as definedby the shapes of the inner openings 2064 i, 2066 i and positions of theprotrusions 2070 p relative thereto.

As mentioned above, the puck 735 of FIG. 5 is configured to have thesame torque limits for both firm closure and quick closure of the endeffector. However, a puck of a tool assembly can be configured toindependently limit the torque for firm closure of an end effector ofthe tool assembly and for quick closure of the end effector. Thisindependent control of torque limits may allow for more precise controlof firm closure and quick closure.

FIG. 14 illustrates one embodiment of a closure assembly thatindependently limits the torque for firm closure of an end effector of atool assembly and for quick closure of the end effector. The closureassembly includes a quick closure assembly 2074, shown in FIGS. 14 and15, configured to limit the torque provided by a motor, e.g., the fourthmotor M4 of FIG. 5, for quick closure of an end effector, e.g., the endeffector 438 of FIG. 4. The quick closure assembly 2074 can be a finalgear in a gear train for quick closure, e.g., the quick closure assembly2074 can be used in place of the quick close gear G4 b of FIG. 5. Theclosure assembly also includes a firm closure assembly 2076, shown inFIGS. 14 and 17, configured to limit the torque provided by a motor.e.g., the fourth motor M4 of FIG. 5, for quick closure of an endeffector, e.g., the end effector 438 of FIG. 4. The firm closureassembly 2076 can be a final gear in a gear train for firm closure,e.g., the firm closure assembly 2076 can be used in place of the firmclose gear G4 a of FIG. 5.

As shown in FIGS. 14-16, the quick closure assembly 2074 includes a gear2078 having an inner opening 2078 i defined by a perimeter 2078 p, acoupler 2080 having one or more protrusions 2080 p extending radiallyoutward from a perimeter thereof, and a washer 2082. The gear 2078 andthe coupler 2080 are generally configured and used similar to thatdiscussed above regarding the first gear 2066 and the coupler 2070 ofFIG. 13. The inner opening 2078 i is configured to cooperate with thecoupler 2080 to provide a torque limit when the motor operativelycoupled thereto drives clockwise and counterclockwise rotation. Theperimeter 2078 p defines stop surfaces for each of clockwise andcounterclockwise rotation such that the quick closure assembly 2074 isconfigured to provide torque limits regardless of a direction that themotor drives gear rotation. The torque limits are the same in both theclockwise and counterclockwise directions, as defined by the shapes ofthe inner opening 2078 i and positions of the protrusions 2080 prelative thereto, that allows the gear 2078 to slip over the coupler2080 when the protrusions 2080 p abut the perimeter 2078 p during gear2078 rotation. The torque limits can instead be different in theclockwise and counterclockwise directions, as defined by the shapes ofthe inner opening 2078 i and positions of the protrusions 2080 prelative thereto, such as by having a first limit for “backward”movement and a second, lower limit for “forward” movement.

As shown in FIGS. 14, 17, and 18, the firm closure assembly 2076includes a gear 2084 having an inner opening 2084 i defined by aperimeter 2084 p, a coupler 2086 having one or more protrusions 2086 pextending radially outward from a perimeter thereof, and a washer 2088.The gear 2084 and the coupler 2086 are generally configured and usedsimilar to that discussed above regarding the first gear 2066 and thecoupler 2070 of FIG. 13. The inner opening 2084 i is configured tocooperate with the coupler 2086 to provide a torque limit when the motoroperatively coupled thereto drives clockwise and counterclockwiserotation. The perimeter 2084 p defines stop surfaces for each ofclockwise and counterclockwise rotation such that the firm closureassembly 2076 is configured to provide torque limits regardless of adirection that the motor drives gear rotation. The torque limits are thesame in both the clockwise and counterclockwise directions, as definedby the shapes of the inner opening 2084 i and positions of theprotrusions 2086 p relative thereto, that allows the gear 2084 to slipover the coupler 2086 when the protrusions 2086 p abut the perimeter2084 p during gear 2084 rotation. The torque limits can instead bedifferent in the clockwise and counterclockwise directions, as definedby the shapes of the inner opening 2084 i and positions of theprotrusions 2086 p relative thereto, such as by having a first limit for“backward” movement (e.g., no limit at all) and a second, higher limitfor “forward” movement.

As also illustrated in FIG. 14, the puck that includes the quick closureand firm closure assemblies 2074, 2076 can include a firing assembly2090 configured to limit an amount of torque provided to the toolassembly by another motor (e.g., the fifth motor M5 of FIG. 5) foreffecting firing of the end effector. The firing assembly 2090 iseffective to limit the torque for firing of the end effector. The firingassembly 2090 can be a final gear in a gear train for firing, e.g., thefiring assembly 2090 can be used in place of the firing gear G5 of FIG.5. Although the puck includes all three of the firing assembly 2090 andthe quick closure and firm closure assemblies 2074, 2076, a puck caninclude any one or two of the firing assembly 2090 and the quick closureand firm closure assemblies 2074, 2076.

As shown in FIGS. 14, 19, and 20, the firing assembly 2090 includes agear 2092 having an inner opening 2092 i defined by a perimeter 2092 p,a coupler 2094 having one or more protrusions 2094 p extending radiallyoutward from a perimeter thereof, and a washer 2096. The gear 2092 andthe coupler 2094 are generally configured and used similar to thatdiscussed above regarding the first gear 2054 and the coupler 2058 ofFIG. 13. The inner opening 2092 i is configured to cooperate with thecoupler 2094 to provide a torque limit when the motor operativelycoupled thereto drives clockwise and counterclockwise rotation. Theperimeter 2092 p defines a stop surface for only one of clockwise andcounterclockwise rotation. The gear 2092 is free to rotate in acounterclockwise direction without engaging the protrusions 2094 p.Torque is thus not limited by the firing assembly 2090 when the motorassociated therewith drives counterclockwise rotation, which isassociated with “backward” movement (e.g., knife retraction), therebyallowing for faster correction of, e.g., inadvertent cutting. Theperimeter 2092 p defines a stop surface for each of the protrusions 2094p such that when the gear 2092 rotates in a clockwise direction, theprotrusions 2094 p will each abut their respective stop surfaces at acertain point during the gear's rotation. Torque provided by the motorwill thus stop driving the gear's rotation. The firing assembly 2090 isthus configured to limit torque. Clockwise rotation of the gear 2090 isassociated with “forward” movement (e.g., knife advancement), therebyallowing for cutting to stop at a certain point so matter (e.g., tissue)firing does not occur too fast and/or the knife does not cut too fast.

Torque limiting mechanisms for closure (both for quick closure and firmclosure) and for firing are discussed above. In alternative to all or inaddition to any one or more of the closure and firing torque limitingmechanisms, a puck of a tool assembly can include one or more torquelimiting mechanisms associated with one or more other functions of anend effector of the tool assembly. For example, the puck can include anyone or more of a torque limiting mechanism for articulation, e.g., onetorque limiting mechanism for both of the first and second articulationgears G1. G2 of FIG. 5 or a torque limiting mechanism for each of thefirst and second articulation gears G1, G2 of FIG. 5, and a torquelimiting mechanism for rotation, e.g., one torque limiting mechanism forboth of the shaft rotation gear G3 a and the head rotation gear G3 b ofFIG. 5 or a torque limiting mechanism for each of the shaft rotationgear G3 a and the head rotation gear G3 b of FIG. 5.

A tool driver has a certain torque capacity, e.g., a predeterminedmaximum amount of available torque, that is appropriate for certaintypes of surgical tools configured to operably couple to the tooldriver, e.g., a robust tool configured to receive an amount of torque upto the certain torque capacity such as an endocutter for stomachfirings, but that is too high for other types of surgical toolsconfigured to operably couple to the tool driver, e.g., less robusttools such as graspers, endocutters for vascular firings, and energydevices. A surgical tool configured to operably couple to the tooldriver can be configured to communicate an identifier to the tool driver(e.g., transmit a signal thereto indicative of the identifier) thatindicates a maximum amount of torque the tool can accept. The tooldriver can be configured to not provide torque to the surgical tool overthe maximum amount of torque that the tool can accept, thereby helpingto ensure proper functioning of the tool without overloading the tool.To not provide too much torque to the tool driver in view of the tool'smaximum amount of acceptable torque, the motors can be adjustedelectrically or mechanically. The electrical adjustment of the motorscan be accomplished, for example, by a series of small pager motorslinked to each of the drive disk mechanisms associated with the motorsconfigured to advance or retract a calming plate behind the mechanicaltorque limiting mechanism, thereby adjusting the motor's slip distancefrom the drive disk and thereby limiting its torque to the slipthreshold. The mechanical adjustment of the motors can be accomplished,for example, by adjusting spacing in an axial direction of the torquelimiters described above. By adjusting a gap between disks in thesetorque limiters, the threshold for slipping is affected, with a largergap corresponding to a lower threshold.

Terminology

There are a number of ways in which to describe the movement of asurgical system, as well as its position and orientation in space. Oneparticularly convenient convention is to characterize a system in termsof its degrees of freedom. The degrees of freedom of a system are thenumber of independent variables that uniquely identify its pose orconfiguration. The set of Cartesian degrees of freedom is usuallyrepresented by the three translational or position variables, e.g.,surge, heave, and sway, and by the three rotational or orientationvariables, e.g., Euler angles or roll, pitch, and yaw, that describe theposition and orientation of a component of a surgical system withrespect to a given reference Cartesian frame. As used herein, and asillustrated in FIG. 21, the term “surge” refers to forward and backwardmovement, the term “heave” refers to movement up and down, and the term“sway” refers to movement left and right. With regard to the rotationalterms, “roll” refers to tilting side to side, “pitch” refers to tiltingforward and backward, and “yaw” refers to turning left and right. In amore general sense, each of the translation terms refers to movementalong one of the three axes in a Cartesian frame, and each of therotational terms refers to rotation about one of the three axes in aCartesian frame.

Although the number of degrees of freedom is at most six, a condition inwhich all the translational and orientation variables are independentlycontrolled, the number of joint degrees of freedom is generally theresult of design choices that involve considerations of the complexityof the mechanism and the task specifications. For non-redundantkinematic chains, the number of independently controlled joints is equalto the degree of mobility for an end effector. For redundant kinematicchains, the end effector will have an equal number of degrees of freedomin Cartesian space that will correspond to a combination oftranslational and rotational motions. Accordingly, the number of degreesof freedom can be more than, equal to, or less than six.

With regard to characterizing the position of various components of thesurgical system and the mechanical frame, the terms “forward” and“rearward” may be used. In general, the term “forward” refers to an endof the surgical system that is closest to the distal end of the inputtool, and when in use in a surgical procedure, to the end disposedwithin a patient's body. The term “rearward” refers to an end of thesurgical system farthest from the distal end of the input tool, and whenin use, generally to the end farther from the patient.

The terminology used herein is not intended to limit the invention. Forexample, spatially relative terms, e.g., “superior,” “inferior,”“beneath,” “below,” “lower,” “above,” “upper,” “rearward,” “forward,”etc., may be used to describe one element's or feature's relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positionsand orientations of the device in use or operation in addition to theposition and orientation shown in the figures. For example, if thedevice in the figures is turned over, elements described as “inferiorto” or “below” other elements or features would then be “superior to” or“above” the other elements or features. Likewise, descriptions ofmovement along and around various axes include various special devicepositions and orientations. As will be appreciated by those skilled inthe art, specification of the presence of stated features, steps,operations, elements, and/or components does not preclude the presenceor addition of one or more other features, steps, operations, elements,components, and/or groups described herein. In addition, componentsdescribed as coupled may be directly coupled, or they may be indirectlycoupled via one or more intermediate components.

There are several general aspects that apply to the various descriptionsbelow. For example, at least one surgical end effector is shown anddescribed in various figures. An end effector is the part of a surgicalinstrument or assembly that performs a specific surgical function, e.g.,forceps/graspers, needle drivers, scissors, electrocautery hooks,staplers, clip appliers/removers, suction tools, irrigation tools, etc.Any end effector can be utilized with the surgical systems describedherein. Further, in exemplary embodiments, an end effector can beconfigured to be manipulated by a user input tool. The input tool can beany tool that allows successful manipulation of the end effector,whether it be a tool similar in shape and style to the end effector,such as an input tool of scissors similar to end effector scissors, or atool that is different in shape and style to the end effector, such asan input tool of a glove dissimilar to end effector graspers, and suchas an input tool of a joystick dissimilar to end effector graspers. Insome embodiments, the input tool can be a larger scaled version of theend effector to facilitate ease of use. Such a larger scale input toolcan have finger loops or grips of a size suitable for a user to hold.However, the end effector and the input tool can have any relative size.

A slave tool, e.g., a surgical instrument, of the surgical system can bepositioned inside a patient's body cavity through an access point in atissue surface for minimally invasive surgical procedures. Typically,cannulas such as trocars are used to provide a pathway through a tissuesurface and/or to prevent a surgical instrument or guide tube fromrubbing on patient tissue. Cannulas can be used for both incisions andnatural orifices. Some surgical procedures require insufflation, and thecannula can include one or more seals to prevent excess insufflation gasleakage past the instrument or guide tube. In some embodiments, thecannula can have a housing coupled thereto with two or more sealed portsfor receiving various types of instruments besides the slave assembly.As will be appreciated by a person skilled in the art, any of thesurgical system components disclosed herein can have a functional sealdisposed thereon, therein, and/or therearound to prevent and/or reduceinsufflation leakage while any portion of the surgical system isdisposed through a surgical access port, such as a cannula. The surgicalsystems can also be used in open surgical procedures. As used herein, asurgical access point is a point at which the slave tool enters a bodycavity through a tissue surface, whether through a cannula in aminimally invasive procedure or through an incision in an openprocedure.

Computer Systems

The systems, devices, and methods disclosed herein can be implementedusing one or more computer systems, which may also be referred to hereinas digital data processing systems and programmable systems.

One or more aspects or features of the subject matter described hereincan be realized in digital electronic circuitry, integrated circuitry,specially designed application specific integrated circuits (ASICs),field programmable gate arrays (FPGAs) computer hardware, firmware,software, and/or combinations thereof. These various aspects or featurescan include implementation in one or more computer programs that areexecutable and/or interpretable on a programmable system including atleast one programmable processor, which can be special or generalpurpose, coupled to receive data and instructions from, and to transmitdata and instructions to, a storage system, at least one input device,and at least one output device. The programmable system or computersystem may include clients and servers. A client and server aregenerally remote from each other and typically interact through acommunication network. The relationship of client and server arises byvirtue of computer programs running on the respective computers andhaving a client-server relationship to each other.

The computer programs, which can also be referred to as programs,software, software applications, applications, components, or code,include machine instructions for a programmable processor, and can beimplemented in a high-level procedural language, an object-orientedprogramming language, a functional programming language, a logicalprogramming language, and/or in assembly/machine language. As usedherein, the term “machine-readable medium” refers to any computerprogram product, apparatus and/or device, such as for example magneticdiscs, optical disks, memory, and Programmable Logic Devices (PLDs),used to provide machine instructions and/or data to a programmableprocessor, including a machine-readable medium that receives machineinstructions as a machine-readable signal. The term “machine-readablesignal” refers to any signal used to provide machine instructions and/ordata to a programmable processor. The machine-readable medium can storesuch machine instructions non-transitorily, such as for example as woulda non-transient solid-state memory or a magnetic hard drive or anyequivalent storage medium. The machine-readable medium can alternativelyor additionally store such machine instructions in a transient manner,such as for example as would a processor cache or other random accessmemory associated with one or more physical processor cores.

To provide for interaction with a user, one or more aspects or featuresof the subject matter described herein can be implemented on a computerhaving a display device, such as for example a cathode ray tube (CRT) ora liquid crystal display (LCD) or a light emitting diode (LED) monitorfor displaying information to the user and a keyboard and a pointingdevice, e.g., a mouse, a trackball, etc., by which the user may provideinput to the computer. Other kinds of devices can be used to provide forinteraction with a user as well. For example, feedback provided to theuser can be any form of sensory feedback, such as for example visualfeedback, auditory feedback, or tactile feedback; and input from theuser may be received in any form, including, but not limited to,acoustic, speech, or tactile input. Other possible input devicesinclude, but are not limited to, touch screens or other touch-sensitivedevices such as single or multi-point resistive or capacitive trackpads,voice recognition hardware and software, optical scanners, opticalpointers, digital image capture devices and associated interpretationsoftware, and the like.

FIG. 22 illustrates one exemplary embodiment of a computer system 100.As shown, the computer system 100 includes one or more processors 102which can control the operation of the computer system 100. “Processors”are also referred to herein as “controllers.” The processor(s) 102 caninclude any type of microprocessor or central processing unit (CPU),including programmable general-purpose or special-purposemicroprocessors and/or any one of a variety of proprietary orcommercially available single or multi-processor systems. The computersystem 100 can also include one or more memories 104, which can providetemporary storage for code to be executed by the processor(s) 102 or fordata acquired from one or more users, storage devices, and/or databases.The memory 104 can include read-only memory (ROM), flash memory, one ormore varieties of random access memory (RAM) (e.g., static RAM (SRAM),dynamic RAM (DRAM), or synchronous DRAM (SDRAM)), and/or a combinationof memory technologies.

The various elements of the computer system 100 can be coupled to a bussystem 112. The illustrated bus system 112 is an abstraction thatrepresents any one or more separate physical busses, communicationlines/interfaces, and/or multi-drop or point-to-point connections,connected by appropriate bridges, adapters, and/or controllers. Thecomputer system 100 can also include one or more network interface(s)106, one or more input/output (IO) interface(s) 108, and one or morestorage device(s) 110.

The network interface(s) 106 can enable the computer system 100 tocommunicate with remote devices, e.g., other computer systems, over anetwork, and can be, for non-limiting example, remote desktop connectioninterfaces, Ethernet adapters, and/or other local area network (LAN)adapters. The IO interface(s) 108 can include one or more interfacecomponents to connect the computer system 100 with other electronicequipment. For non-limiting example, the IO interface(s) 108 can includehigh speed data ports, such as universal serial bus (USB) ports, 1394ports, Wi-Fi, Bluetooth, etc. Additionally, the computer system 100 canbe accessible to a human user, and thus the IO interface(s) 108 caninclude displays, speakers, keyboards, pointing devices, and/or variousother video, audio, or alphanumeric interfaces. The storage device(s)110 can include any conventional medium for storing data in anon-volatile and/or non-transient manner. The storage device(s) 110 canthus hold data and/or instructions in a persistent state, i.e., thevalue(s) are retained despite interruption of power to the computersystem 100. The storage device(s) 110 can include one or more hard diskdrives, flash drives, USB drives, optical drives, various media cards,diskettes, compact discs, and/or any combination thereof and can bedirectly connected to the computer system 100 or remotely connectedthereto, such as over a network. In an exemplary embodiment, the storagedevice(s) can include a tangible or non-transitory computer readablemedium configured to store data, e.g., a hard disk drive, a flash drive,a USB drive, an optical drive, a media card, a diskette, a compact disc,etc.

The elements illustrated in FIG. 22 can be some or all of the elementsof a single physical machine. In addition, not all of the illustratedelements need to be located on or in the same physical machine.Exemplary computer systems include conventional desktop computers,workstations, minicomputers, laptop computers, tablet computers,personal digital assistants (PDAs), mobile phones, and the like.

The computer system 100 can include a web browser for retrieving webpages or other markup language streams, presenting those pages and/orstreams (visually, aurally, or otherwise), executing scripts, controlsand other code on those pages/streams, accepting user input with respectto those pages/streams (e.g., for purposes of completing input fields),issuing HyperText Transfer Protocol (HTTP) requests with respect tothose pages/streams or otherwise (e.g., for submitting to a serverinformation from the completed input fields), and so forth. The webpages or other markup language can be in HyperText Markup Language(HTML) or other conventional forms, including embedded Extensible MarkupLanguage (XML), scripts, controls, and so forth. The computer system 100can also include a web server for generating and/or delivering the webpages to client computer systems.

In an exemplary embodiment, the computer system 100 can be provided as asingle unit, e.g., as a single server, as a single tower, containedwithin a single housing, etc. The single unit can be modular such thatvarious aspects thereof can be swapped in and out as needed for, e.g.,upgrade, replacement, maintenance, etc., without interruptingfunctionality of any other aspects of the system. The single unit canthus also be scalable with the ability to be added to as additionalmodules and/or additional functionality of existing modules are desiredand/or improved upon.

A computer system can also include any of a variety of other softwareand/or hardware components, including by way of non-limiting example,operating systems and database management systems. Although an exemplarycomputer system is depicted and described herein, it will be appreciatedthat this is for sake of generality and convenience. In otherembodiments, the computer system may differ in architecture andoperation from that shown and described here.

Reuse

The devices disclosed herein can also be designed to be disposed ofafter a single use, or they can be designed to be used multiple times.In either case, however, the device can be reconditioned for reuse afterat least one use. Reconditioning can include any combination of thesteps of disassembly of the device, followed by cleaning or replacementof particular pieces and subsequent reassembly. In particular, thedevice can be disassembled, and any number of the particular pieces orparts of the device can be selectively replaced or removed in anycombination. Upon cleaning and/or replacement of particular parts, thedevice can be reassembled for subsequent use either at a reconditioningfacility, or by a surgical team immediately prior to a surgicalprocedure. Those skilled in the art will appreciate that reconditioningof a device can utilize a variety of techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of the presentapplication.

Preferably, components of the invention described herein will beprocessed before use. First, a new or used instrument is obtained and ifnecessary cleaned. The instrument can then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK bag. The container and instrumentare then placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high energy electrons.The radiation kills bacteria on the instrument and in the container. Thesterilized instrument can then be stored in the sterile container. Thesealed container keeps the instrument sterile until it is opened in themedical facility.

Typically, the device is sterilized. This can be done by any number ofways known to those skilled in the art including beta or gammaradiation, ethylene oxide, steam, and a liquid bath (e.g., cold soak).An exemplary embodiment of sterilizing a device including internalcircuitry is described in more detail in U.S. Pat. No. 8,114,345 filedFeb. 8, 2008 and entitled “System And Method Of Sterilizing AnImplantable Medical Device.” It is preferred that device, if implanted,is hermetically sealed. This can be done by any number of ways known tothose skilled in the art.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

What is claimed is:
 1. A surgical system, comprising: a first motor of arobotic surgical system, the robotic surgical system being configured toreleasably and replaceably couple to a surgical tool, and the firstmotor having a maximum torque output; a first actuator of the roboticsurgical system, the first motor being configured to apply an amount oftorque to the first actuator and thereby cause movement of an endeffector of the surgical tool, in which the amount of torque applied bythe first motor to the first actuator does not exceed a first torquethreshold that is less than the maximum torque output; a second actuatorof the robotic surgical system, the first motor being configured toapply an amount of torque to the second actuator and thereby causemovement of the end effector of the surgical tool, in which the amountof torque applied by the first motor to the second actuator does notexceed a second torque threshold that is less than the maximum torqueoutput and that is different from the first torque threshold; a secondmotor of the robotic surgical system; and a third actuator of therobotic surgical system; wherein the first motor is a single motor, andthe second motor is configured to apply an amount of torque to the thirdactuator and thereby cause movement of the end effector of the surgicaltool.
 2. The system of claim 1, wherein the movement of the end effectorcaused by the amount of torque applied to the first actuator isdifferent from the movement of the end effector caused by the amount oftorque applied to the second actuator.
 3. The system of claim 2, whereinthe movement of the end effector caused by the amount of torque appliedto the first actuator is closing of the end effector at a first speed,and the movement of the end effector caused by the amount of torqueapplied to the second actuator is closing the end effector at a secondspeed that is greater than the first speed.
 4. The system of claim 1,further comprising a first torque limiting mechanism configured toprevent the amount of torque applied by the first motor to the firstactuator from exceeding the first torque threshold; and a second torquelimiting mechanism configured to prevent the amount of torque applied bythe first motor to the second actuator from exceeding the second torquethreshold.
 5. The system of claim 4, wherein the first and second torquelimiting mechanisms each include a rotatable gear.
 6. The system ofclaim 1, wherein the first and second actuators each include a rotatablegear.
 7. The system of claim 1, further comprising a tool driverincluding the first motor and the first and second actuators, the tooldriver being configured to releasably and replaceably couple to ahousing of the surgical tool.
 8. The system of claim 1, wherein thesurgical tool is a surgical stapler.
 9. A surgical system, comprising: amotor of a robotic surgical system, the robotic surgical system beingconfigured to releasably and replaceably couple to a surgical tool, andthe motor having a maximum torque output; a first actuator of therobotic surgical system, the motor being configured to apply an amountof torque to the first actuator and thereby cause a first movement of anend effector of the surgical tool; a first torque limiting mechanismconfigured to prevent the amount of torque applied by the motor to thefirst actuator from exceeding a first torque threshold that is less thanthe maximum torque output; a second actuator of the robotic surgicalsystem, the motor being configured to apply an amount of torque to thesecond actuator and thereby cause a second movement of the end effectorof the surgical tool, the second movement being different from the firstmovement; and a second torque limiting mechanism configured to preventthe amount of torque applied by the motor to the second actuator fromexceeding a second torque threshold that is less than the maximum torqueoutput and that is different from the first torque threshold.
 10. Thesystem of claim 9, further comprising an additional motor of the roboticsurgical system, and an additional actuator of the robotic surgicalsystem; wherein the motor is a single motor, and the additional motor isconfigured to apply an amount of torque to the additional actuator andthereby cause movement of the end effector.
 11. The system of claim 9,wherein the first torque limiting mechanism includes engaged first andsecond rotatable members; and the second torque limiting mechanismincludes engaged third and fourth rotatable members.
 12. The system ofclaim 9, wherein the first and second actuators each include a rotatablegear.
 13. The system of claim 9, further comprising a tool driverincluding the motor and the first and second actuators, the tool driverbeing configured to releasably and replaceably couple to a housing ofthe surgical tool.
 14. The system of claim 9, wherein the surgical toolis a surgical stapler.
 15. A surgical method, comprising: rotating afirst gear of a robotic surgical system to actuate a single motor of therobotic surgical system so as to output a first amount of torque andthereby cause an end effector of a surgical tool operatively coupled tothe single motor to cause a first movement of the end effector in a bodyof a patient; preventing the first amount of torque output by the singlemotor from exceeding a first torque threshold that is less than themaximum torque output; rotating a second gear of the robotic surgicalsystem to actuate the single motor so as to output a second amount oftorque and thereby cause a second movement of the end effector in thebody of the patient that is different from the first movement of the endeffector; and preventing the second amount of torque output by thesingle motor from exceeding a second torque threshold that is less thanthe maximum torque output and that is different from the first torquethreshold.
 16. The method of claim 15, wherein preventing the firstamount of torque output by the single motor from exceeding the firsttorque threshold includes engagement of first and second rotatablemembers; and preventing the second amount of torque output by the singlemotor from exceeding the second torque threshold includes engagement ofthird and fourth rotatable members.
 17. A surgical method, comprising:actuating a single motor of a robotic surgical system to output a firstamount of torque and thereby cause an end effector of a surgical tooloperatively coupled to the single motor to cause a first movement of theend effector in a body of a patient; preventing the first amount oftorque output by the motor from exceeding a first torque threshold thatis less than the maximum torque output; actuating the single motor ofthe robotic surgical system to output a second amount of torque andthereby cause a second movement of the end effector in the body of thepatient that is different from the first movement of the end effector;preventing the second amount of torque output by the motor fromexceeding a second torque threshold that is less than the maximum torqueoutput and that is different from the first torque threshold; andactuating an additional motor of the robotic surgical system to output athird amount of torque and thereby cause a third movement of the endeffector in the body of the patient that is different from the first andsecond movements of the end effector.
 18. The method of claim 15,further comprising releasably engaging a tool driver of the roboticsurgical system to a proximal housing of the surgical tool, the endeffector being located at a distal end of the surgical tool.
 19. Themethod of claim 17, further comprising releasably engaging a tool driverof the robotic surgical system to a proximal housing of the surgicaltool, the end effector being located at a distal end of the surgicaltool.